Textiles are used in various applications as an interface between an object or body part and an underlying surface to avoid direct contact between the object/body part and the underlying surface. In many such applications, a slip-resistant bottom layer, usually formed from a polymeric material, is added to the textile to prevent or minimize slippage or shearing between the textile and the underlying surface. Some examples include coasters, floor mats, dining placemats, and footwear insoles. As many of these applications may result in the textile being soiled, it is desirable to employ fabrics that can be repeatedly washed and dried, preferably using a washing machine and dryer. Although many fabrics are generally washable, many polymeric materials that are currently used to increase adherence to an underlying surface (e.g., a floor, shelf, footbed, etc.) are not washable.
When people wear shoes they almost always wear socks. Socks create friction between the foot and shoe for better engagement of foot motions by the shoe, absorb moisture perspired by the foot, create a path between the shoe and skin of the foot to allow air to circulate about the foot, and can keep the foot warm in cold weather or cool in hot weather. However, people wear a number of shoe styles without socks, such as, various sandals, deck shoes, etc. When not wearing socks, the sole of the foot is almost in constant contact with the upper surface of the footbed.
On a hot day a sandal wearer can be very comfortable everywhere but at the sole of the foot. The intimate contact between the foot sole and the footbed of the footwear leaves no room for air to circulate under the foot and can cause considerable sweat under foot. This can be uncomfortable and it can also result in footwear that carries odor.
The problem of lack of breathability at the interface between the footwear and the foot is exacerbated by modern synthetic materials. Some of these synthetic materials can be worse for breathability than traditional materials and can increase both the problem of foot sweat and of footwear odor. For instance, the smooth vinyl foam of the popular Crocs® sandals, when in intimate contact with the sole, can lead to substantial sweating. Many insoles are nothing more than polymer sheets pressed into a shape and are not particularly breathable.
To prevent sweating and foot odor, people often wear socks with sandals and other types of open footwear. However, many people find this aesthetically unappealing. In addition, one loses much of the benefit of wearing open footwear when wearing socks.
Mechanically, open footwear doesn't lend itself to maintaining a breathable textile under foot in the way that a sock maintains itself about the foot. For example, open footwear doesn't capture and retain an insole in place like closed sole footwear, such as a shoe. To solve this, adhesives have been used to bond a fabric insole in place against the footbed of the footwear. Unfortunately, the adhesives do generally not retain their chemistries through the wash cycle of a laundry. Adhesives can delaminate from the textile, and they do not prevent certain textiles from shrinking. Furthermore, adhesives may stick too well to areas of the footbed and can remove portions of the footbed when the insole is removed from the shoe. To overcome the inability to wash the textile, much of the prior art suggests the use of perfume or odor fighting chemistry to hide or mitigate odor.
Ultimately what is needed is a variety of textiles, appropriate for different conditions (warm materials for cool weather, cool materials for warm weather) that can adhere to a footbed (or other substrate in other applications). These textiles desirably should be removable from footwear without pulling out parts of the footbed. These textiles should be washable with household laundry without worry about shrinkage and wearable afterwards. They should be robust to an indefinite number of wash and wear cycles.